Update to this post.
So I worked down the list of possible causes to this P-0171 code from the cheapest fix on up. I recently replaced the FPR and no suprise to me, it didn't get rid of the code, it poped up very shortly after I cleared it with the OBD II scanner. I also checked the fuel pressure using a bango fitting and some creativity and the fuel pressure was within spec. (I wish Toyota installed a schrader valve on the fuel rail from the factory)
The only thing left to replace was the injector$$...
I looked at sending the injectors off for cleaning and inspection but decided not to due to shipping cost, down time..... Anyway, I bought new OEM injectors from
Discount Auto Parts Online -- PartsGeek.com - Domestic & Import Auto Parts Warehouse and installed them. The result? Instant increase in power and, (knock on the dash) no codes. The power loss over a long time wasn't really notable, it ran great, didn't stall, stumble, get bad milage, smoke, use any fluids. I thought, especially after I installed the BIG tires, that was to be expected. But now the 4Rocker runs like it's near new.
I want to express my opinion about stuff you buy in bottles that you pour into your vehicle to fix its woes. As a means of preventative maintenance maybe... but if you have an issue that needs to be fixed, no amount of snake oil will fix your ills! The only thing that works is elbow grease and new parts. I spent the cost of one or two new injectors on 44K, Lucas, etc.... wasted money IMHO. This is pour advice! Ha ha ha... Leason learned!
My gut at the onset of this problem said fuel injectors but my long term plan is to replace the engine so now I know the fuel system is rebuilt too.
I want to thank the T4R members how offered their helpful advise.
Put down the seafoam and get to work.
